Don't use the truck much unless I'm towing or need large vehicle for something, so this oil has gone 6k miles in two years. Curious about the Copper & Silver levels. I Installed a ball bearing turbo about 1k miles before the oil was changed, so I'm hoping that has something to do with it. Moly seems lower than I expected.Wondering how long I should run this batch?

The Si is not silver, but Silica (or silicone; both are seen the same by spectral analysis). Silica is dirt ingestion. This Si level may be accounting for a bit of the Fe, but not a lot.

I'd not do anything to it except upon the next OCI, do another UOA and see if the wear metals come down a bit.

The ol' 7.3PSD is a good engine and has plenty of life left in her. With only 93k miles in 14 years, it's not likely you'll ever wear it out.

The act of preventative maintenance, in and of itself, is FAR MORE important than brand/grade/base choices among lubes and filters. - under maintaining something is akin to abuse/neglect; that can kill equipment by shortening the lifespan- over maintaining something has never been proven to be anything but a waste of time and money

Has sheared back to 30wt. One one hand, with the viscosity loss and considering the elevated metals, a change might be good. But on the other hand, the TBN is great still at 6.89, so it definitely has the additive levels to go longer. Maybe run it another 3-4K and sample again, paying particular attention to the rate of metal wear per 1000 miles.

The HEUI loves to shear oil down to a 30 wt, and the 7.3's for the most part seem to happy with it, so I m not too concerned about the viscosity. Schaeffer flagged it for the silver (Ag) level, so that's what I'm most curious about. Guessing ball bearings in the new turbo? Checking for air leaks as silica is higher than I would expect with the AIS air cleaner I'm running.

To be clear, the silver (Ag) and the silica (Si) are not the same thing. I thought you were looking at the Si, but I now see the Ag is a bit up as well. I'm not used to looking for Ag in a UOA. I'm not sure of the source of the Ag.

The Si would be of more concern to me. Not that the level of Si is "bad", but a tad elevated. However, given that the engine had a turbo removed and installed, it's possible that amount is elevated from the work. If it drops upon the next OCI, no issues whatsoever.

Last edited by dnewton3; 08/11/1705:50 AM.

The act of preventative maintenance, in and of itself, is FAR MORE important than brand/grade/base choices among lubes and filters. - under maintaining something is akin to abuse/neglect; that can kill equipment by shortening the lifespan- over maintaining something has never been proven to be anything but a waste of time and money